Constant tension device



July 29, 1952 D. E. HOWE CONSTANT TENSION DEVICE Filed May 15 1948 l'snnentor DOA ALB 5. 190/715 (Itfornegs In the drawings:

the apparatus,

Patented July 29, 1952 UNITED STATES PATENT Donald E. Howe, Akron, Ohio, assignor to The J Firestone Tire & Rubber Company, Akron,

Ohio, a corporation of Ohio Application May 12, 1943, Serial No. 26,791

2 Claims. (015242-155) it is. understood that the invention is not limited to such use. I

A further object of the invention is generally to improve the .construction and operation of mechanisms adapted to maintain cord-like elements under constant tension during a stretching operation with particular reference to the application thereof within the textile field. Cotton cord as currently employed in tire construction is normally subjected to a stretching operation after being twisted. To permit the use of relatively simple apparatus, a constant percent elongation is commonly applied, although stretch under a constant load results in more uniform physical properties such as residual stretch and tensile strength. 4

v Fig. 1 is a view in perspective of one form of Fig. 2 is a View in perspective of another form .of the apparatus, V Fig. 3 is an end elevational View ofa third form of the apparatus, and

. Fig. 4 is a side elevational view of the device vof Fig. 3.

. Referring to the drawings, Fig. 1 discloses a constant load or tension device representing one adaptation of the invention. The device comprises a" lever arm in, pivoted at H to a pair of stationary brackets l2. One end of lever arm l0 providesipull fora cylindrical receptacle l4, consisting of a side wall I5, a closed bottom wall l6- and an upper end open to the atmosphere. A bracket comprising a pair of bifurcated arms I8 is fixed to bottom wall [6 to depend therefrom for pivotal engagement through pintle bolt with arm 10.

Receptacle M has concentrically disposed therein a stationary vane assembly 22 consisting of a cylinder 23 and a plurality of radial arms 24 extending from a tubular hub 25 outwardly to cylinder 22. The lower end of cylinder 22 may contiguously'engage the inner surface of bottom wall 16; A shaft is journalled at 3| to a fixed bracket 32.- The upper end of shaft 301carries thread pulley 34 in pressed fit or keyed relation thereto. Cord 35, being'processed, partially surrounds upper groove 36 in double pulley 34, passes around an idler pulley 31 and then makesone complete turn around the lower groove '38 of'pulley 34. The cord is thus in non-slip engagement with pulley 34. Upon leaving pulley 34, a

the cord moves-over a pulley 40 andthen down .and around pulle'ydZ-rotatably mountedat the left end of lever 'Hl, thence upward andover pulley M and on to a subsequent winding'or processing stage. r The lower end of shaft 30 carries a vane assembly 46 .which. rotates therewith, assembly 46 preferably being of the same: diameter as the previously described fixed vane assembly. .Shaft 30 extends through-vane assembly 46 andlinto hub '26 .of the fixed vane assembly to retain said assemblies concentrically aligned while permitting axial movement therebetween. Vane assembly 46 might have the samenumber of'vanes as the lower fixed assemblyif desired. Provision of a weight 543, hung from lever It! at a suitable position in respect to lever 42 as determined by the magnitude of the weight and the amount of tension to be applied, completes the assembly except for the addition of suitable fluidwithin receptacle l4 sufiicient to completely immerse the lower vane assembly and at least partially immerse the upper vane assembly. The operation of thedeviceis evident from the drawing and may be briefly outlined as follows. Cord 35, being threaded, is moved about pulleys 34,31 34, 40, 12 and 44 by the application of suitable pulling force applied to'the cord at a pointto the left of pulley M in the directionof the arrow. 'While pulleys 31, All, 42'-and 44 are mounted for free rotation inrespect to their various mounting shafts which are fixed in a manner not shown, pulley 34-rotates in respect to journal 3i but is fixed in respect to shaft 30. The tensionengagement of cord 35 in respect to the grooves 36 and 38 of pulley 34 imparts sufficient frictional engagement to prevent slippage of the cord'35' in grooves 36'and 33 of pulley 34, hence-rate'of rotation of uppervane assembly -46 is a function of jtherate;'of cord movement. The degreeof tension applied to cord 35'determines the relative position of pivoted lever 10, through pulley 42, since variation in the magnitude of applied tension, working against weight 50 (as partially balanced by the dead weight of receptacle l4 and its contents) determines that position. R0 tation of upper vane assembly 45 in response to cord movement effects a fluid drag between the juxtaposed vane assembly which varies in an inverse proportion to the axial distance therebetween. It is radially seen that a sudden increase of applied pulling force to the left of pulley 44 will result in upward movement of pulley 42 with the result of pivoting movements of lever H! in a direction to lower receptacle l4 and increasefthe axial distance between the vane assembly to decrease the hydraulic drag on the tendant pivotal movement of lever H) in the direction to move receptacle in an upward direction and decrease the axial distance between the vane assemblies with resultant increase in the hydraulic drag imparted to the cord through pulley 34.

An alternate adaptation of the invention is disclosed in Fig. 2, wherein hydraulic drag is automatically applied in varying degrees t'o the thread :rotation therewith. .FIhread 135, tobe.processed, .is fed. in the arrow direction around .double igrooved'pulley :74, thence to idlerxpulleysafl, and back around pulley 11d :and then downwardly to partially encircle Lpulley 69 and upwardly in the .arroW'direction. v The tension force is applied in the direction of the upwardly extending arrow at atapoint' not shown. In operation, the device works -'-in a manner similar to thestructure of Fig.1, with the exception that weight '10 is not partially counter-balanced. Pulley "l4 acts' as the gearpump drive and in this manner its function is similar to pulley :34 of the'Fig. -l adaptation.

Thread 135 drives pulley I'M without slippage therebetween astlie thread substantially'encircles the pulley twice prior'to its partial encirclement of'the-lever pulley-69. The fluid drag imparted to the thread b ;gear pump 60 zislazfunction of the setting of valve 62, in the sameFm'anner-that :the fluid drag imparted by pulley .34 in'the first adaptation was the function i the position of =levei' arm ID as it pivoted inrespectto'itspintle t. 'Increaseinthe applied tensioning .force applied-to thread 35in the'upward arrow direction results in anupward movement-ofv-pulley -fifi with a corresponding pivoting of lever 68 about its fulcrum 8! to increase the opening 0f valve-.62 and thereby decrease the now resistance in the system against which gear-pump fillrmustwork.

A- corresponding decrease :in-th e applied tensionpressure-is accomplished .byra lowering of pulley 69 and ipi-votingrof "lever-68 in adownward direction resulting in a movement of valve '62 toward its closed position, increasing the flow-resistance .of the circuit and thereby increasing the fluid .drag as imparted to the cord by'pulley 14.

A still further adaptation .of-athe invention :is illustrated in'Figss3-and awhereinaleverfi, piv- .oted-at.86.to a bracket81, iscounterebalancedby reason of a pulley -assembly 8.8 beingiixed to one arm thereof and adjustable weights $2 .mou-nted on the other-arm thereof. .Bulley Jassemblyfit includes a brakedrum-SO and a thread-receiving .pulley -9l "mounted as a unit for rotation on :a shaft extension'of lever 85, asshowntat'95, Fig. 3. A dep-endingarmesfi is fixed to-the shait'extension 95 at the free end'thereof to provideuoffset anchorage for idler-,pulley-sl. A vlowli e-shoe 98 functionally engages the portion of drum 90 under the 'urge of compression ,spring fl Oil confined between the-brake --shoe and .bracket ill] :Shoe 9a is carried-by lever steer-mamma to a standard l-il-carriedby the weightleverti.

In operation, the-device of 3 and A resemhles Fig. 1 with the exception that a frictional resistance drag replaces the hydraulic drag of Fig. 1 device. Variations inthe tensioning force, which in this instance isapplied in the downward direction as shown by the arrows, result in variations in frictional resistances between drum 90 and shoe 98 as lever pivots about fulcrum 86 in response to such pressure variations. Weights 92 through adjustability longitudinally ofthe lever arm 85, provide a convenient means for introducing the correct equilibrium between the load and the tension for a given thread, hence spring 106 need not be provided with adjusting means.

The preferred embodiments of the invention ,are .above described for the purpose .of )illustra- .tion irather than limitation," it :being understood that ;further..structural modifications may :?freely .be'resorted' Eto without departure .from the: spirit andoscope of the invention which is limited ,only

, by the :claims zappendant'hereto.

What :is claimed :is:

'1. ,A-xievice for impartinga constant tension to continuously :moving material, .icompri'sing means to apply a lateral force to saidilmoving 1material, aipulleylpositioned in advance :df isaid first imeans over which :said .;material passes,' Fa brake adapted to.apply a restraining. forceztoasaid ;pulleyicomprising. a;containericontainingrai liquid, 2. waned rotor 1132.111; immersed in rsaid liquid and connected :to and rotatable with said pulley,i:a 'vaned stator :part immersed in :said liquid and connected to :said means, said.stator'part :being movable toward and away from said irot'or :by said means whereby to: exert a avariableiizestnain- Eingiorceiomsaid rotor.and-saidipulley.

.2. :A'device for imparting a constant tensionzto continuouslymoving'material.comprisingeaipulley 7 attached to one end of a lever anditaki'rrgaposition laterally offset from the line of' travlof said material means :to urge said zpulley away 'from said line of travel, a second pulle'y' position'e'd in advance of said 'firstpulley over which sa-iiimaterial passes, a brake adapted toapplya-restrainingdorce tosaid second'pulleycomprising-acontainer containing a liquid, a varied rotor-part immersed in said liquid and connected to and rotatable with said second pulley, a vaned stator part imm'ersed'in said liquid and connectedto' the other end of said we -opposit e saidiirstgpulley and movable "toward andaway-from said rotorin accordance. with' the position taken by said? lever and first pulley "to exert "a variable restraining i-orce'upon'said *rotor'and second? pulley.

"DONALD, E. news. REFERENCES ease The following references are of record in-sthe file -of=thispatentz Umian SI'A 'I-fES' PA 'I-EN TS j number .iDare Frame.a.nn nneanahsai 

